auto calculating formula or macro, not sure.

Looking for a =SUM or =Vlookup or other formula/macro that can average 15 minutes of data based upon a THEORITICAL VALUE. Ideally, I would like to have the THEORITICAL VALUE in the formula and not reference a cell. I tried fooling around combining nested =countifs() formulas from other threads but failed.
The attached file provides a more descriptive explanation. Thanks in advance. MP

I've been fooling around with Solver for this but not sure if that works. Also the above file did not have the solver loaded into it when I uploaded it.